Thermodynamics of distribution of para-substituted phenols between organic solvents and sodium chloride solution

The distribution of para-substituted phenols between 8 organic solvents and 0.15 mol · dm⁻³ NaCl solution has been determined at five different temperatures using the shake-flask technique and the thermodynamic parameters for the process (ΔH and ΔS) evaluated from the van't Hoff isochore. The free energy change for the transfer of the methylene group from water to organic solvent was entropically controlled. Logarithms of distribution constants of phenols for a given organic solvent—water system were linearly related to those for other solvent systems and also to the substituent constant of Hansch. The influence of the nature of the organic solvent upon the distribution constants of phenols and the incremental distribution constants per methene group could be evaluated by the Regular Solution theory.